Comparative quality of winter food sources for cirl bunting delivered through countryside stewardship special project and CS arable options
Published source details RSPB . (2004) Comparative quality of winter food sources for cirl bunting delivered through countryside stewardship special project and CS arable options. DEFRA report, project ref. BD1626.
Actions
This study is summarised as evidence for the following.
| Action | Category | |
|---|---|---|
Leave overwinter stubbles Action Link |  | |
Plant wild bird seed or cover mixture Action Link | |
Leave overwinter stubbles
A replicated, randomized study from November 2003 to March 2004 in 205 cereal stubble fields under a range of management intensities in arable farmland in south Devon, UK (Defra 2004) found that barley stubbles following low-input herbicide were more beneficial for cirl bunting Emberiza cirlus than wheat or conventionally managed stubbles. The number of breeding cirl bunting territories the previous season and small field size (probably, as the authors point out, because cirl buntings prefer to forage near hedgerows and because smaller fields are less intensively managed) also correlated positively with population size. Overall, barley fields were generally preferred by seed-eating species. Low-input barley stubbles had significantly higher seed abundance and broadleaved weed cover (approximately four times greater). Fields where stubbles were grazed over winter led to significantly lower densities of seed-eating birds in general. The authors point out that seed-eating bird species’ preference for barley stubbles was independent of the positive correlation with broadleaved weed density and should be taken into account when planning prescriptions.
Plant wild bird seed or cover mixture
A replicated, randomized study from November 2003 to March 2004 in 205 cereal stubble fields in arable farmland in south Devon, UK (Defra 2004) found no clear changes in habitat use by seed-eating birds after the establishment of wild bird cover crops on some stubble fields. The target species, cirl bunting Emberiza cirlus, made insignificant use of wild bird cover crops (average of 2 individuals/plot). Only two plots contained more than five individuals and use of the habitat dropped drastically in March, which the authors suggest makes the habitat a poor alternative to stubbles. High numbers of other seed-eating species including chaffinch Fringilla coelebs and yellowhammer Emberiza citrinella were recorded on the wild bird cover crops, especially those containing a mixture of rape, millet, linseed Linum usitatissimum, kale Brassica spp. and quinoa Chenopodium quinoa (maximum seed-eating bird count 491 on wild bird cover vs 191 on barley fields). Only song thrush Turdus philomelos abundance was significantly positively related to wild bird cover presence. However, few stubble fields contained wild bird cover crops (13 fields with 24 wild bird cover strips) and the results may have been confounded by low sample size.
